How to verify that file2 is newer than file1 in bash

I'm not sure what you're after, but this should work for quick checks:

ls -tl

You could do this:

TM_LOCAL=$(ls -l --time-style=long-iso ~/.vimrc | \
             awk '{ print $6" "$7 }' ; exit ${PIPESTATUS[0]} )

Then $? will be the return code from ls. This doesn't work if you need the return code from more than one of the pipe parts (but you could split the pipeline if the output isn't too large, as it is here).

Here's a rather expensive way of getting the full PIPESTATUS array and the output. Not very elegant, but haven't found anything else:

result=$(echo -e "a\nb\nc" | \
          ( cat ; exit 1 ) | \
          ( cat ; exit 42 ) ; echo ${PIPESTATUS[@]})
output=$(head -n -1 <<< "$result")
status=($(tail -n 1 <<< "$result"))
echo "Output:"
echo "$output"
echo "Results:"
echo "${status[@]}"

Which gives:

Output:
a
b
c
Results:
0 1 42